Hydrogen production by water dissociation in surface-modified BaCo _xFe_yZr_(1-x-y)O_(3-δ) hollow-fiber membrane reactor with improved oxygen permeation

摘要

A porous perovskite BaCo_x,Fe_yZr _(0.9-x-y)Pd_(0.1)O_(3-δ) (BCFZ-Pd) coating was deposited onto the outer surface of a BaCO_xFe_yZr _(1-x-y)O_(3-δ) (BCFZ) perovskite hollow-fiber membrane. The surface morphology of the modified BCFZ fiber was characterized by scanning electron microscopy (SEM), indicating the formation of a BCFZ-Pd porous layer on the outer surface of a dense BCFZ hollow-fiber membrane. The oxygen permeation flux of the BCFZ membrane with a BCFZ-Pd porous layer increased 3.5 times more than that of the blank BCFZ membrane when feeding reactive CH4 onto the permeation side of the membrane. The blank BCFZ membrane and surface-modified BCFZ membrane were used as reactors to shift the equilibrium of thermal water dissociation for hydrogen production because they allow the selective removal of the produced oxygen from the water dissociation system. It was found that the hydrogen production rate increased from 0.7 to 2.1 mLH_2min ~(-1)VCm~(-2) at 950°C after depositing a BCFZ-Pd porous layer onto the BCFZ membrane.